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View Full Version : SBC Valve Adjustment


AHorseThief
12-18-2011, 08:30 PM
Not terribly pertinent to anyone not running a SBC, but I've been hemming and hawing over how to best adjust the valves on my 327 for a week or so. The valve train has been noisy ever since I got it.

Depending on who you ask, you can either adjust by finding TDC twice, or bumping the engine around all the cylinders. Both of these methods use the spin the rod until it don't spin as good method.

The alternative method is to adjust with the engine running, backing off until the valve makes noise, adjusting in until it just stops, and then going an extra 1/4 to 1/2 turn.

I tried adjusting by bumping the engine, but I wasn't terribly satisfied with the results. Prepared to make a huge mess, I decided to try the "while running" method. Most guys advocating this method get plugs or make a set of valve covers with a window to keep the oil in. I decided to just be fast.

I've got to say that doing it with the engine running took out all of the guess work and wasn't that messy in the grand scheme of things. Between the valve job and a new set of plugs the engine sounds much happier now.

RicardoJM
12-19-2011, 08:11 AM
Nice job Nick. Working on the rig and the ensuing feeling of accomplishment is one the things I like about wrenching.

rover67
12-19-2011, 09:50 AM
That sounds like fun. There is a thread on mud in the 60's forum where some guy did it on his 2f and people gave him all the reasons why it wouldn't work. It was nice to see him do it and it is nice to see you doing it :)

nuclearlemon
12-19-2011, 10:12 AM
i've always done it running. you can get oil deflector clips for the rockers that supposedly keep the oil from spraying all over, but i've never had any issues with the oil spraying wildly.

black95
12-19-2011, 10:51 AM
Once you tighten the rocker and remove all lash from the pushrod, you have to give the rocker nut another 1/2 to 3/4 turn, then they're set. I tried the cover off method once, and mine was very messy. Had one cylinder that wouldn't stay quiet, but found out later it was a bad lifter...

Air Randy
12-19-2011, 08:19 PM
Once you tighten the rocker and remove all lash from the pushrod, you have to give the rocker nut another 1/2 to 3/4 turn, then they're set. I tried the cover off method once, and mine was very messy. Had one cylinder that wouldn't stay quiet, but found out later it was a bad lifter...

Only if you are running hydraulic lifters. Then the "zero lash plus 1/2 turn" method centers the pushrod in the lifter chamber. If you are running solid lifters though, you only want to tighten the rockers down until you reach zero lash while you also have the right size feeler gauge inserted. Otherwise you will be set too tight and might start burning valves.